Several theories suggest that owning household pets may have a wide range of beneficial health effects such as reduced risk of obesity, improved social adjustment, and positive cardiovascular outcomes. If these health effects are representative of the effects in the general population, then pet ownership may have significant public health benefits. Unfortunately, these effects have generally been found in small-scale studies or convenience samples rather than large representative samples. In addition, the existing literature generally does not investigate whether the observed associations between health and pet ownership should be attributed to pet ownership. Most of the existing research examining the association of pet ownership with health and wellbeing has failed to control for selection effects related to pet ownership. The current proposal seeks to address these two limitations in the existing scientific literature using existing data from the California Health Interview Survey (CHIS). The sample is designed to be fully representative of the state of California. The survey measures a wide range of health outcomes including overall physical health, mental health, social development, physical activity, obesity, and asthma;as well as a wide range of demographic, socioeconomic and family environment variables. In 2003, CHIS surveyed 42,000 adults and asked about dogs and cats living in their households. CHIS also interviewed more than 12,500 children under age 18 in these sampled households. These data will allow the research team to examine the association between living with dogs and/or cats and several important health outcomes using a large, representative sample of children in the general population. The proposed analyses will address two specific aims: (1) Determine whether the effects found previously in small or convenience samples replicate in a general population of children and adolescents and (2) Separate the health effects of pet ownership itself from the effects of characteristics associated with pet ownership. The analysis will use state of the art statistical methods to make rigorous estimates of the effects of pet ownership on health while controlling for a very broad range of individual, household and regional characteristics associated with pet ownership. Moreover, the data are already available, so that the impact of the proposed research can be achieved relatively quickly and at low- cost for such a large-scale epidemiological investigation. PUBLIC HEALTH RELEVANCE: Millions of American households include a dog or a cat and preliminary research suggests that these pets may have significant public health effects. Using existing data from a large epidemiological study, this project will document the overall public health effects of living with dogs and cats on children and adolescents.